This invention relates to air deflectors used on trucks to reduce wind resistance created by turbulence between the truck cab and the larger rearward body including cabs fixed to bodies and cabs with trailer bodies and including refrigeration units on the truck body rearward of the cab.
U.S. Pat. No. 3,934,923 discloses a porous structure mounted on the cab roof to pass air into the gap between the cab and trailer body to act as a barrier to airflow into the gap at the top and sides. The structure is a flat plate with perforations situated below the plane of the refrigeration unit attached to a front wall of a rearward trailer. The plate is perforated to minimize drag by creating eddie air currents in the space between the cab and trailer. Air flows over the top edge of the deflector to the refrigeration unit, the top edge being significantly lower than the refrigeration unit.
U.S. Pat. No. 4,567,734 discloses an air deflector discloses a louvered housing over the refrigeration unit. This does not address the problem of drag resistance created by the turbulence due to the difference in dimensions of the cab to the rear cargo carrying body.
U.S. Pat. No. 4,611,796 discloses a fairing for aerodynamically braking a tractor-trailer combination utilizing a central pivoting fast acting door within a roof mounted aerodynamic fairing to selectively expose and conceal the front surface of the trailer, masked by the fairing. The door is operated cooperatively with the vehicles brakes. When the door is closed minimum drag is provided and when the door is open maximum drag occurs to assist in braking.
U.S. Pat. No. 4,957,325 discloses an aerodynamically enhanced air grill mounted on a vehicle with an air intake grill and a pair of air discharge grills. This is a louvered box-like structure placed on the roof of a truck cab. An interior V-shaped deflector barrier is also used behind the intake grill. This structure due to its boxy non-aerodynamic shape may provide undesirable drag air currents.
U.S. Pat. No. 5,317,880 discloses a complex louvered structure to control air passing over a tractor trailer. It provides variable redirection of air flow to allow desired effects to be met. It provides for ventilation and cooling for a refrigeration unit and for brake components via air ducts. Air drag can be created selectively to assist in braking. In the louver closed position the refrigeration unit may overheat requiring the louvers to be opened.
Other louvered air deflectors for truck cab roofs are shown in U.S. Pat. Nos. 5,092,648, 5,653,493 and 5,876,088.
An air deflector to reduce turbulence drag according to the present invention for a vehicle including a cab and body, the body being different in size than the cab causing turbulent air resistance between the cab and body, and a refrigeration unit attached to the body front wall adjacent to the cab, the deflector for reducing the turbulent air resistance and comprises first and second spaced side walls and an interconnected top wall; a front wall coupled to the side and top wall; and an air scoop defining a recess in the deflector front wall and connected to the side walls and top wall for directing inlet air to the refrigeration unit.
In one aspect, one of the side and top walls have an opening for exhausting hot air from the refrigeration unit to the ambient atmosphere.
In another aspect, the side walls are arranged to receive the refrigeration unit therebetween so that the refrigeration unit is closely spaced to the scoop.
In a further aspect, the top wall has a U-shaped through opening at a rear edge distal the deflector front wall for exhausting hot air from the refrigeration unit.
In a further aspect, the scoop has a rear wall distal the front wall, the rear wall including a lattice grill.
The deflector of the present invention thus includes a scoop which collects and directs inlet air directly toward the refrigeration unit to supply the unit a high volume of air for the heat exchanger of the unit. The scoop has sides that insure a major portion of the inlet air is directed at the refrigeration unit rather than deflected away from the refrigeration unit by air eddie currents. The refrigeration unit may abut directly against the scoop rear grill. The refrigeration unit generated hot air is then exhausted through the opening in the housing top wall to the ambient atmosphere.